Re: [dpdk-dev] [PATCH V2] ethdev: add dev configured flag

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

@David, could you take a look at the ABI breakage warnings for
the patch. May we ignore it since ABI looks backward
compatible? Or should be marked as a minor change ABI
which is backward compatible with DPDK_21?

On 7/6/21 7:10 AM, Huisong Li wrote:
> Currently, if dev_configure is not called or fails to be called, users
> can still call dev_start successfully. So it is necessary to have a flag
> which indicates whether the device is configured, to control whether
> dev_start can be called and eliminate dependency on user invocation order.
> 
> The flag stored in "struct rte_eth_dev_data" is more reasonable than
>  "enum rte_eth_dev_state". "enum rte_eth_dev_state" is private to the
> primary and secondary processes, and can be independently controlled.
> However, the secondary process does not make resource allocations and
> does not call dev_configure(). These are done by the primary process
> and can be obtained or used by the secondary process. So this patch
> adds a "dev_configured" flag in "rte_eth_dev_data", like "dev_started".
> 
> Signed-off-by: Huisong Li <lihuisong@huawei.com>

Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>

> ---
> v1 -> v2:
>   - adjusting the description of patch.
> 
> ---
>  lib/ethdev/rte_ethdev.c      | 16 ++++++++++++++++
>  lib/ethdev/rte_ethdev_core.h |  6 +++++-
>  2 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index c607eab..6540432 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -1356,6 +1356,13 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
>  		return -EBUSY;
>  	}
>  
> +	/*
> +	 * Ensure that "dev_configured" is always 0 each time prepare to do
> +	 * dev_configure() to avoid any non-anticipated behaviour.
> +	 * And set to 1 when dev_configure() is executed successfully.
> +	 */
> +	dev->data->dev_configured = 0;
> +
>  	 /* Store original config, as rollback required on failure */
>  	memcpy(&orig_conf, &dev->data->dev_conf, sizeof(dev->data->dev_conf));
>  
> @@ -1606,6 +1613,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
>  	}
>  
>  	rte_ethdev_trace_configure(port_id, nb_rx_q, nb_tx_q, dev_conf, 0);
> +	dev->data->dev_configured = 1;
> +

I think it should be inserted before the trace, since tracing
is intentionally put close to return without any empty lines
in between.

>  	return 0;
>  reset_queues:
>  	eth_dev_rx_queue_config(dev, 0);
> @@ -1751,6 +1760,13 @@ rte_eth_dev_start(uint16_t port_id)
>  
>  	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_start, -ENOTSUP);
>  
> +	if (dev->data->dev_configured == 0) {
> +		RTE_ETHDEV_LOG(INFO,
> +			"Device with port_id=%"PRIu16" is not configured.\n",
> +			port_id);
> +		return -EINVAL;
> +	}
> +
>  	if (dev->data->dev_started != 0) {
>  		RTE_ETHDEV_LOG(INFO,
>  			"Device with port_id=%"PRIu16" already started\n",
> diff --git a/lib/ethdev/rte_ethdev_core.h b/lib/ethdev/rte_ethdev_core.h
> index 4679d94..edf96de 100644
> --- a/lib/ethdev/rte_ethdev_core.h
> +++ b/lib/ethdev/rte_ethdev_core.h
> @@ -167,7 +167,11 @@ struct rte_eth_dev_data {
>  		scattered_rx : 1,  /**< RX of scattered packets is ON(1) / OFF(0) */
>  		all_multicast : 1, /**< RX all multicast mode ON(1) / OFF(0). */
>  		dev_started : 1,   /**< Device state: STARTED(1) / STOPPED(0). */
> -		lro         : 1;   /**< RX LRO is ON(1) / OFF(0) */
> +		lro         : 1,   /**< RX LRO is ON(1) / OFF(0) */
> +		dev_configured : 1;
> +		/**< Indicates whether the device is configured.
> +		 *   CONFIGURED(1) / NOT CONFIGURED(0).
> +		 */
>  	uint8_t rx_queue_state[RTE_MAX_QUEUES_PER_PORT];
>  		/**< Queues state: HAIRPIN(2) / STARTED(1) / STOPPED(0). */
>  	uint8_t tx_queue_state[RTE_MAX_QUEUES_PER_PORT];
>